1. Field of the Invention
The present invention relates to an art of electrical connectors, more specifically, to an electrical connector for electrically connecting a memory module or the like to a printed circuit board (PCB).
2. Description of Related Art
With the development of electronic industry, performance of an electrical connector is increasingly required. As a result, the structure of the connector turns to be increasingly complex and manufacturing of the electrical connector becomes increasingly difficult. For example, in order to prevent terminals from loosening in a housing of the electrical connector, a conventional technology is provided to stamp one side of the housing where the terminal is secured nearby. Therefore, an interference between the terminal and the housing is gained by proper deformation of the housing by stamping, which provide a firm securing of the terminal in the housing.
Referring to FIGS. 8–14, a conventional electrical connector for connecting a memory module to a PCB is shown. The electrical connector includes a longitudinal dielectric housing 60 and a number of terminals 70 received in the housing 60. The housing 60 defines a lengthwise inserting face 61, an bottom face 62 opposite to the inserting face 61, and two opposite side walls 63 perpendicular to both the inserting face 61 and bottom face 62. A number of receiving holes 65 cut through housing 60 from inserting face 61 to bottom face 62. Each receiving hole 65 is defined with a first mating surface 651 and a second mating surface 652, both parallel to the side face 63, and the first mating surface 651 closer to the side face 63. The terminal 70 includes a sheet-like retention portion 72, an arcuate contacting portion 74 extending upwardly from an upper end of the retention portion 72 and an inserting portion 76 extending downwardly from a lower end of the retention portion 72. The retention portion 72 protrudes a pair of stoppers 78 along two opposite lateral sides of the retention portion 72. The stoppers 78 are used to control the depth of the terminal 70 inserted into the housing 60. Furthermore, the retention portion 72 has a first and a second retention faces 721, 722 for interferentially mating with the first and second mating surfaces 651, 652, respectively. The contacting portion 74 is used for contacting a golden finger of a memory module or the like. The inserting portion 76 is soldered to a PCB.
In assembling the electrical connector, insert the terminals 70 through the inserting face 61 into the receiving holes 65 until the stoppers 78 are blocked against the housing 60, mount the connector onto the PCB, the inserting portion 76 of the terminal 70 being inserted into a hole (not shown) defined beforehand in a PCB corresponding to the terminal 70, solder the inserting portion 76 to the PCB, so electrical connection between the electrical connector and the PCB is defined.
However, in said assembling, all the terminals 70 of the connector need to be inserted into corresponding holes in the PCB at the same time, and it is impossible to align all the terminals 70 to corresponding holes synchronously, so some of the terminals 70, which are deflected from corresponding holes in the PCB, tend to draw back and even release from the housing 60 during the insertion, which will negatively effect the electrical connection between the electrical connector and the PCB. In order to insure the quality of the electrical connection between the electrical connector and the PCB, the retention forces of the terminals 70 need to be increased.
To increase the retention forces of the terminals 70 in the receiving holes 65, a conventional technology is to dimple a line of dents 69 equidistantly arranged on the side face 63 of the housing 60. With the dents deflecting the side face 63, the first mating surfaces 651 displace inwardly partly. So the amount of an interference between the terminals 70 and the first mating surface 651 increases and the force of the housing 60 gripping the contact 70 increases accordingly. In order to further improve the retention forces of the terminals 70 in the receiving holes 65, conventionally, a number of protrusions 7211 are stamped out on the first retention face 721 of the retention portion 72 to increase the amount of the interference between the terminal 70 and the housing 60.
However, when the retention portion 72 is stamped out the protrusion 7211 on the first retention face 721, there is always a recess 7222 defined on the second retention face 722. So when the first mating surface 651 is stamped towards the first retention face 721 of the terminal 70, the protrusions 7211 are usually pressed down, and thus, the retention force of the terminal 70 in the housing 60 is impaired.